Oligosaccharides composition for preventing or reducing the risk of metabolic syndrome

ABSTRACT

The present invention relates to the use of a galactooligosaccharide composition for preventing or reducing the risk of developing metabolic syndrome.

The present invention relates to a composition comprising a mixture ofgalactooligosaccharides for use in a method for the prevention orreduction of the risk of developing metabolic syndrome. It also relatesto a method of preventing or reducing the risk of developing metabolicsyndrome by orally administering a composition comprising a mixture ofgalactooligosaccharides. Galactooligosaccharides are non-digestiblecarbohydrates which are resistant to mammalian gastrointestinaldigestive enzymes but are fermented by specific colonic bacteria.

Metabolic syndrome is the name given to a group of risk factors thatoccur together and that result in an increase in the risk ofcardiovascular disorders such as coronary artery disease, heart disease,heart attack and heart damage, as well as increased risk of stroke.

There have been several definitions of metabolic syndrome but the mostcommonly used one at present is the World Health Organisation (WHO)definition.

According to WHO the criteria or risk factors for metabolic syndromeare 1) central obesity with a waist:hip ratio above 0.9 for men and 0.85for women; 2) body mass index (BMI) above 30 kg/m²; 3) blood pressureabove 140/90; 4) triglycerides above 1.7 mmol/1; 5) high densitylipoprotein (HDL) cholesterol <0.9 mmol/1 in men and <1 mmol/1 in women;6) glucose fasting or 2 hours after a glucose load above 7.8 mmol/1 and7) glucose uptake during hyperinsulinaemic euglycaemic clamp in lowestquartile for population.

In general, an individual's risk of heart disease, diabetes and strokeincreases with the number of metabolic risk factors they have. A personwho has metabolic syndrome is twice as likely to develop heart diseaseand five times as likely to develop diabetes as someone who does nothave metabolic syndrome.

To date, the goal of managing metabolic syndrome is to reduce the riskof heart disease and diabetes. Doctors usually recommend lifestylechanges and/or prescribe medicines, such as a combination ofbeta-blockers, diuretics and/or a daily low-dose of aspirin to reduceblood pressure, low density lipoprotein (LDL) cholesterol and bloodsugar. Recommendations for lifestyle changes will include weight loss,probably by eating 500-1,000 fewer calories per day, and 30 minutes ofmoderate intensity exercise, such as walking, 5-7 days per week.

It has now been found in a double-blind randomised, placebo controlled,cross-over human trial that oral administration of a compositioncomprising a mixture of galactooligosaccharides can lower cholesteroland triglyceride levels in the blood and thus be used in a method forthe prevention or reduction of the risk of developing metabolicsyndrome.

The mixture of galactooligosaccharides comprised disaccharides Gal(ß1-3)-Glc; Gal (ß1-3)-Gal; Gale (ß1-6)-Gal; Gal (α1-6)-Gal;trisaccharides Gal (ß1-6)-Gal (ß1-4)-Glc; Gal (ß1-3)-Gal (ß1-4)-Glc;tetrasaccharide Gal (ß1-6)-Gal (ß1-6)-Gal (ß1-4)-Glc and pentasacharideGal (ß1-6)-Gal (ß1-6)-Gal (ß1-6)-Gal (ß1-4)-Glc.

This mixture of galactooligosaccharides is disclosed in EP 1 644 482,which describes a novel strain of Bifidobacterium bifidum that producesa galactosidase enzyme activity that converts lactose to this novelmixture of galactooligosaccharides. This novel mixture has been shown tohave prebiotic and anti-inflammatory properties in the gut.

This mixture of galactooligosaccharides is marketed commercially underthe name Bimuno (registered trade m ark) and is available from ClasadoLtd (Milton Keynes, UK).

According to one aspect of the invention there is provided a compositioncomprising a mixture of galactooligosaccharides as defined above for usein a method for preventing or reducing the risk of developing metabolicsyndrome.

This mixture of galactooligosaccharides may also be used in a method forthe prevention of cardiovascular disorders such as coronary arterydisease, coronary heart disease, heart attack and stroke. An effectiveamount of galactooligosaccharide is preferably administered daily as asingle dose or alternatively as two separate doses several hours apart.

According to a second aspect of the invention there is provided a methodof preventing or reducing the risk of developing metabolic syndromecomprising administering to a mammal such as a human an effective amountof a galactooligosaccharide composition comprising a mixture ofgalactooligosaccharides as defined above.

The product known as Bimuno comprises at least 49% of the dry matter asthe mixture of galactooligosaccharides. The remainder of the compositionmay comprise non-active components such as glucose, galactose, lactose,acacia gum and citric acid.

The composition may be presented in freeze-dried powder form, in syrupform or in pastille form. It is preferably taken orally on a dailybasis. The powder composition preferably comprises from 1.35 g to 9.6 gof galactooligosaccharide in 2.75 g to 20 g of the powdered composition,preferably from 1.96 g to 4.9 g of galactooligosaccharide in 4 g to 10 gof the powder, most preferably 2.7 g galactooligosaccharide in 5.5 g ofcomposition. The composition may be added to a drink, preferably a hotdrink, or sprinkled on food, for example, on breakfast cereal.

Alternatively, the galactooligosaccharide may be presented as a syrup orpastilles (dehydrated syrup) in which the non-active components maycomprise glucose, galactose, lactose and citric acid. A daily dose ofthe syrup may comprise from 1.35 g to 9.6 g of thegalactooligosaccharide mixture in 3.55 g to 25.29 g of the syrupcomposition, preferably from 1.96 g to 4.9 g of galactooligosaccharidein 5.16 g to 12.9 g of the syrup, most preferably 2.7 ggalactooligosacchride in 7.25 g of the syrup.

The invention will be further described by way of reference to thefollowing examples: —

EXAMPLE 1

Freeze-dried powdered composition packaged in a ‘stick-pack’ andcontaining per 5.5 g final product:—

Galactooligosaccharide (GOS) mixture 2.75 g Lactose 1.40 gMonosaccharides (glucose, galactose) 0.64 g Drying aid 0.24 g Ash 0.23 gMoisture 0.19 g Protein 0.05 g

EXAMPLE 2

Syrup composition per 7.25 g finished product:—

Galactooligosaccharide (GOS) mixture 2.75 g Lactose 0.58 gMonosaccharides (glucose, galactose) 1.69 g Ash 0.23 g Moisture 1.95 gProtein 0.05 g

EXAMPLE 3

Effectiveness of galactooligosaccharides on metabolic syndrome riskfactors in overweight adults

Study

A total of 45-50 human subjects with three or more risk factorsassociated with metabolic syndrome and its increased risk ofcardiovascular disease were recruited. Equal numbers of men and womenwere included in the study cohort.

Metabolic syndrome factors used to select subjects included: insulinresistance (measured as increased ratio of fasting glucose (6-7 mmol/1)and insulin), high blood pressure, dyslipidaemia [low high densitylipoprotein (HDL) cholesterol (<1 mmol/1), high triglyceride (>1.3mmol/1)], waist circumference (>40 in men; >35 in women).

Further inclusion criteria were:—

-   -   18-65 years    -   BMI >25 kg/m²    -   not having suffered a myocardial infarction/stroke or cancer in        the past 12 months    -   not diabetic (diagnosed or fasting glucose >7 mmol/l) or        suffering from other endocrine disorders    -   not suffering from chronic coronary, renal, bowel        disease/gastrointestinal disorder or having a history of        choleostatic liver or pancreatitis    -   not on drug treatment for hyperlipidaemia, hypertension,        inflammation, hypercoagulation or using drugs that affect        intestinal motility or absorption    -   no history of alcohol/drug abuse    -   not planning or on a weight reducing regime    -   not taking any dietary antioxidant or other phytochemical,        prebiotics or probiotic supplements    -   not pregnant, lactating, planning a pregnancy in the next 6        month or of child bearing potential and not using effective        contraceptive precautions    -   not taking antibiotics for the previous 1 month    -   not anaemic (haemoglobin men >14 g/dl; women >11.5 g/dl)    -   non smokers

Volunteers who met the inclusion criteria were asked to attend ascreening session during which a fasting (12 hours) blood sample wastaken and their BMI, waist circumference and blood pressure measured.The screening blood sample (˜10 ml) was analysed at the Royal BerkshireHospital for total cholesterol (TC), HDL cholesterol, triacylglycerol,glucose and insulin. Individuals who were anaemic (Hb<14 g/dl male, 11.5g/dl female) or who had ‘abnormal’ blood biochemistry based on the aboveanalysis, were automatically excluded. The measurements were used toidentify individuals at higher metabolic risk, who were then invited toparticipate in the study.

Treatment A or B was randomly assigned to each participant using anallocation ratio of 1:1 for the 2 study groups (including stratificationfor gender). Volunteers were required to attend the University for atotal of 6 visits. The study was a randomised, controlled, double-blindcrossover trial with Maltodextrin as the placebo. Volunteers wereinstructed to ingest the test product (GOS) and/or placebo daily for 12weeks, with a 6 week washout period between. Both GOS and placebo weresupplied in powder sachets (5.5 g) and volunteers were instructed toeither sprinkle these over a bowl of cereal or add them to any drink,and ingest them daily. Habitual diet was assessed by pre-validated 4-dayfood diaries (2 weekend and 2 week days). At 0, 6 and 12 wk ofintervention, volunteers visited the nutrition unit and samples andmeasurements were taken.

On each visit a fasting blood sample (˜20 ml) as taken and this was usedto analyse a number of risk markers (all using commercially availablekits). The markers studied were:

Lipid profile (total, low density lipoprotein (LDL) and HDL cholesterol,triglycerides and non-esterified fatty acids)

Insulin resistance derived from fasted measures of glucose and insulinratio

Inflammatory/thrombotic biomarkers (including C-reactive protein, andIL6)

At 0, 12, 18 and 30 weeks a series of anthroprometric measurements(including weight, blood pressure and waist circumference) were taken inorder to determine any changes.

Results Baseline Characteristics of Subjects

The demographic characteristics of the study population are presented inTable 1.

TABLE 1 Baseline characteristics of subjects participating in the study.Characteristics Male (n = 16) Female (n = 29) Age (yr)  42.8 ± 12.1 46.4± 11.8 BMI (kg/m²) 30.7 ± 5.3 32.1 ± 6.3  Waist circumference (cm) 103.7± 11.0 99.2 ± 14.5 Fasting insulin (pmol/L)  66.3 ± 28.3 70.3 ± 30.6Fasting glucose (mmol/L)  5.5 ± 0.8 5.2 ± 0.6 Systolic Blood Pressure(mmHg) 127.9 ± 10.1 125.9 ± 15.8  Diastolic Blood Pressure (mmHg) 80.9 ±8.6 80.5 ± 10.0 Total Cholesterol (mmol/L)  6.3 ± 1.5 6.2 ± 1.2 HDLcholesterol (mmol/L)  1.3 ± 0.4 1.4 ± 0.3 TAG (mmol/L)  1.9 ± 0.9 1.4 ±0.5

Effect on Colonic Microbiota

Daily consumption of 5.5 g of Bimuno (2.75 g active GOS) showed after 6wk to result in a significant increase in the bifidobacterial populationcompared to both the Placebo (1 wk) (p<0.05) and baseline (p<0.05)levels (Table 2). After 12 wk of consumption, Bimuno intake resulted insignificant increase in the populations of Bifidobacterium andLactobacillus spp compared to Placebo (12 wk) (p<0.0001) and baseline(p<0.05). At the same time the levels of species of the Clostridiumhystoliticum group and Desulfovibrio spp were significantly reducedcompared to Placebo (12 wk) (p<0.0001) and baseline (p<0.05) (Table 2).

In terms of changes in the populations of Atopobium spp, C. coccoides/E.rectale, E. cylindroides, E. hallii, Clostridium cluster IX, F.prausnitzii cluster, beta-Proteobacteria, Bacteroides spp no significanteffect was recorded either after the intake of Bimuno or Placebo duringthe 12 wks treatment period.

Effect on Biomarkers of Inflammation

Results on the levels of faecal sIgA (secretory immunoglobulin A),faecal calprotectin and blood inflammatory biomarkers (IL-6, CRP) duringthe study periods (Placebo, Bimuno) are shown in Table 3.

Daily intake of Bimuno for 12 weeks resulted in a significant reductionof both secretory IgA (p<0.05 vs Placebo; p<0.01 vs baseline) andcalprotectin (p<0.01 vs placebo; p<0.05 vs baseline) (Table 3). At thesame time a significant reaction in the blood levels of thepro-inflammatory cytokine IL-6 (p<0.05 vs Placebo; p<0.05 vs baseline)and in the inflammatory biomarker C-reactive protein (p<0.05 vs Placebo;p<0.05 vs baseline) was determined after daily intake of Bimuno for 12weeks.

Effect on Metabolic Syndrome Risk Factors

Daily intake of Bimuno for 12 weeks resulted in a significant reductionin blood insulin levels (p<0.05 vs Placebo; p<0.01 vs baseline), bloodtriglycerides (p<0.05 vs placebo; p<0.05 vs baseline), total cholesterol(p<0.05 vs Placebo; p<0.05 vs baseline) and the ratio of totalcholesterol over HDL cholesterol (p<0.05 vs Placebo; p<0.05 vs baseline)indicating an overall reduction of the risk of Metabolic syndrome (Table4).

CONCLUSION

Supplementation with 5.5 g Bimuno (delivering 2.75 g of active GOS) in apopulation at risk of developing metabolic syndrome resulted in asignificant change in the composition of their colonic microbiota byincreasing the resident beneficial bacteria of Bifidobacterium genus andLactobacillus genus, while decreasing the levels of detrimental bacteriasuch as those belonging to the C. hystoliticum subgroup and the sulphatereducing bacteria. This microbiota change resulted in an increase in thecolonisation resistance in the gut reducing the colonic inflammation asseen through the reduction of the calprotectin levels. At the same timeincreased levels of sIgA would suggest a better barrier function of theepithelium which in combination with the reduced colonic inflammationcould result in the reduction of the levels of inflammatory biomarkersin the host (IL-6, CRP).

This overall protection through the improvements in the composition ofthe colonic microbiota and the intestinal barrier function appears tohave a beneficial effect in the levels of insulin, cholesterol andtriglycerides that are known risk factors of metabolic syndrome.

TABLE 2 Changes in the numbers (Log₁₀) of the various bacterial groupsmonitored during the study periods (Placebo, Bimuno), as determined byfluorescent in situ hybridisation (FISH) Placebo 5.5 g Bimuno Wk6 Wk12Wk6 Wk12 Bifidobacterium spp  0.17 ± 0.13  0.3 ± 0.19  0.78 ± 0.23* 1.13 ± 0.29* Lactobacillus- −0.04 ± 0.09 −0.12 ± 0.18  0.24 ± 0.15 0.43 ± 0.22* Enterococcus spp C. hystoliticum group  0.15 ± 0.11  0.23± 0.07  0.12 ± 0.21 −0.61 ± 0.24* Desulfovibrio spp  0.02 ± 0.09 −0.03 ±0.11 −0.04 ± 0.07 −0.63 ± 0.17* *significantly different from Baseline(p < 0.05)

TABLE 3 Changes in the levels of the faecal and blood biomarkers ofinflammation during the study periods (Placebo, Bimuno) Placebo 5.5 gBimuno Wk6 Wk12 Wk6 Wk12 sIgA (ug/g faeces) NA −230 ± 243  NA  902 ±214* Calprotectin (ug/g 2.57 ± 4.03 2.58 ± 3.28 −2.91 ± 3.97  −9.61 ±3.27* faeces) IL-6 (ng/ml) NA  7.97 ± 13.01 NA −33.34 ± 12.9* C-Reactiveprotein 0.46 ± 0.42 0.75 ± 0.40  0.66 ± 0.39  −1.56 ± 0.41* (ng/ml)*significantly different from Baseline (p < 0.05)

TABLE 4 Changes in the levels of insulin, TAG and cholesterol after 12wk supplementation of Placebo or Bimuno Placebo 5.5 g Bimuno Wk6 Wk12Wk6 Wk12 Insulin (pmol/L) 5.15 ± 3.14 7.42 ± 2.89 −0.02 ± 0.07 −10.37 ±3.04* Triglycerides 0.09 ± 0.08 −0.03 ± 0.09  −0.08 ± 0.09  −0.79 ±0.11* (mmol/L) Total Cholesterol 0.14 ± 0.11 0.05 ± 0.06 −0.10 ± 0.08 −0.39 ± 0.12* (mmol/L) Total Cholesterol: 0.01 ± 0.04 −0.06 ± 0.09 −0.19 ± 0.08 −0.44 ± 0.1* HDL *significantly different from Baseline (p< 0.05)

1. A composition comprising a mixture of galactooligosaccharides whichcomprises disaccharides Gal (ßI-3)-Glc; Gal (ßI-3)-Gal; Gal (ßI-6)-Gal;Gal (αI-6)-Gal; trisaccharides Gal (ßI-6)-Gal (ßI-4)-Glc; Gal (ßI-3)-Gal(ßI-4)-Glc; tetrasaccharide Gal (ßI-6)-Gal (ßI-6)-Gal (ßI-4)-Glc andpentasaccharide Gal (ßI-6)-Gal (ßI-6)-Gal (ßI-6)-Gal (ßI-4)-Glc for usein a method for preventing or reducing the risk of developing metabolicsyndrome. 2.-14. (canceled)